Fibers and wipes with epoxidized fatty ester disposed thereon, and methods

ABSTRACT

Fibers, which can be used for making wipes (e.g., antimicrobial wipes), wherein the fibers include a core comprising an aliphatic polyester; and an epoxidized fatty ester having greater than 4.7 wt-% oxirane oxygen, based on the total weight of the epoxidized fatty ester; wherein the epoxidized fatty ester is disposed on the surface of the fiber core.

BACKGROUND

There is a trend to manufacture products from renewable resources forglobal environmental protection. Aliphatic polyesters from renewableresources have found increasing application in materials because oftheir biodegradability and compostability, such as poly(lactic acid);however, such materials may not have suitable shelf-life stability forcertain applications, particularly in environments of high moisturecontent due to degredation from hydrolysis. For extended hydrolyticstability of these aliphatic polyesters, reactive additives are commonlyused to crosslink terminal —OH and/or —CO₂H groups as one of theapproaches. This may significantly change the molecular weight of theoriginal aliphatic polyester, which may affect its processibility andproperties. Thus, there is a need for hydrolytic stabilization ofaliphatic polyesters without reaction between the stabilizer and thealiphatic polyesters.

SUMMARY OF THE DISCLOSURE

The present disclosure provides fibers, which can be used for makingwipes such as wet wipes for cleaning and/or disinfecting (e.g.,antimicrobial wipes). The fibers include aliphatic polyesters with oneor more additives that improve the hydrolytic stability of the fibers.

The one or more hydrolytic stabilizing agents can be distributed on thesurfaces of the fibers made of an aliphatic polyester. Or, fibers madeof an aliphatic polyester can be saturated with an aqueous composition(e.g., a cleaning and/or disinfecting composition) containing one ormore hydrolytic stabilizing agents.

Preferably, the hydrolytic stabilizing agents are selected fromepoxidized fatty esters. More preferably, the hydrolytic stabilizingagents are selected from epoxidized vegetable oils (e.g., from renewableresources).

In one embodiment, the present disclosure provides a fiber thatincludes: a core including an aliphatic polyester; and an epoxidizedfatty ester having greater than 4.7 wt-% oxirane oxygen, based on thetotal weight of the epoxidized fatty ester; wherein the epoxidized fattyester is disposed on the surface of the fiber core in an amount of atleast 0.5 wt-%, based on the total weight of the fiber (i.e., the dryweight of the core and the epoxidized fatty ester and any optionaladditives disposed thereon).

In certain embodiments, the aliphatic polyester is selected from thegroup of poly(lactide), poly(glycolide), poly(lactide-co-glycolide),poly(L-lactide-co-trimethylene carbonate), poly(dioxanone),poly(butylene succinate), poly(butylene adipate), poly(ethyleneadipate), polyhydroxybutyrate, polyhydroxyvalerate, and blends andcopolymers thereof. Preferably, the selected aliphatic polyesters areobtained from renewable resources, such as poly(lactic acid).

In another embodiment, the present disclosure provides a wet wipe thatincludes: an aliphatic polyester fibrous web (e.g., a nonwoven web) asdescribed herein; and an aqueous composition in contact with the fibrousweb. The aqueous composition may also include one or more organicsolvents, such as alcohols (e.g., isopropanol), along with the water.

The aqueous composition can include one or more of an epoxidized fattyester for coating the aliphatic polyester and improving the hydrolyticstability of the aliphatic polyester fibrous web. Alternatively, oradditionally, the aqueous composition can include a surfactant and/or abiocide (dissolved or dispersed in the water).

In yet another embodiment, the present disclosure provides a wet wipethat includes: a fibrous web including fibers that include: a coreincluding an aliphatic polyester; and an epoxidized fatty acid havinggreater than 4.7 wt-% oxirane oxygen, based on the total weight of theepoxidized fatty ester; wherein the epoxidized fatty ester is disposedon the surface of the fiber core in an amount of at least 0.5 wt-%,based on the total weight of the fibers (i.e., dry weight of the fibersincluding the core and the epoxidized fatty ester and any optionaladditives disposed on the fiber core, after removal or the water or anysolvents used to apply the epoxidized fatty ester); and an aqueouscomposition contacting the fibrous web, the aqueous compositionincluding: water; and a surfactant and/or a biocide (dissolved ordispersed in the water).

In still another embodiment, the present disclosure provides a wet wipethat includes: a fibrous web that includes fibers, wherein each fiberincludes a core including an aliphatic polyester; and an aqueouscomposition contacting the fibrous web, wherein the aqueous compositionincludes: water; a surfactant and/or a biocide (dissolved or dispersedin the water); and an epoxidized fatty ester having greater than 4.7wt-% oxirane oxygen, based on the total weight of the epoxidized fattyester; wherein the epoxidized fatty ester is dispersed in the aqueouscomposition in an amount of at least 0.5 wt-%, based on the total weightof the aqueous composition.

In certain embodiments, the aqueous composition includes a surfactant,wherein the wet wipe is a cleaning wipe.

In certain embodiments, the aqueous composition includes a biocide,wherein the wet wipe is a disinfecting wipe.

In certain embodiments, the aqueous composition includes a biocide and asurfactant, wherein the wet wipe is a cleaning/disinfecting wipe.

In certain embodiments, the present disclosure provides a process forimproving the hydrolytic stability of fibers that include an aliphaticpolyester. The method includes: forming fibers (typically, in the formof a fibrous web) including an aliphatic polyester; and depositing anepoxidized fatty ester on the surface of the fibers in an amount of atleast 0.5 wt-%, based on the total weight of the fibers; wherein theepoxidized fatty ester has at least 4.7 wt-% oxirane oxygen, based onthe total weight of the epoxidized fatty ester. The epoxidized fattyester can be deposited out of an aqueous composition. If so, the fiberscan then be dried to remove the water and any organic solvents in theaqueous composition.

In certain embodiments, the present disclosure provides another processfor improving the hydrolytic stability of a fibrous web that includesfibers of an aliphatic polyester. The method includes: forming a fibrousweb including fibers including an aliphatic polyester; providing anaqueous composition that includes water, an epoxidized fatty ester in anamount of at least 0.5 wt-%, based on the total weight of the aqueouscomposition, and optionally, a surfactant and/or a biocide; wherein theepoxidized fatty ester has at least 4.7 wt-% oxirane oxygen, based onthe total weight of the epoxidized fatty ester; and contacting thefibrous web with the aqueous composition to deposit the epoxidized fattyester thereon. The method can optionally include drying the fibrous web.

The terms “comprises” and variations thereof do not have a limitingmeaning where these terms appear in the description and claims. Suchterms will be understood to imply the inclusion of a stated step orelement or group of steps or elements but not the exclusion of any otherstep or element or group of steps or elements. By “consisting of” ismeant including, and limited to, whatever follows the phrase “consistingof.” Thus, the phrase “consisting of” indicates that the listed elementsare required or mandatory, and that no other elements may be present. By“consisting essentially of” is meant including any elements listed afterthe phrase, and limited to other elements that do not interfere with orcontribute to the activity or action specified in the disclosure for thelisted elements. Thus, the phrase “consisting essentially of” indicatesthat the listed elements are required or mandatory, but that otherelements are optional and may or may not be present depending uponwhether or not they materially affect the activity or action of thelisted elements.

The words “preferred” and “preferably” refer to claims of the disclosurethat may afford certain benefits, under certain circumstances. However,other claims may also be preferred, under the same or othercircumstances. Furthermore, the recitation of one or more preferredclaims does not imply that other claims are not useful, and is notintended to exclude other claims from the scope of the disclosure.

In this application, terms such as “a,” “an,” and “the” are not intendedto refer to only a singular entity, but include the general class ofwhich a specific example may be used for illustration. The terms “a,”“an,” and “the” are used interchangeably with the term “at least one.”The phrases “at least one of” and “comprises at least one of” followedby a list refers to any one of the items in the list and any combinationof two or more items in the list.

As used herein, the term “or” is generally employed in its usual senseincluding “and/or” unless the content clearly dictates otherwise.

The term “and/or” means one or all of the listed elements or acombination of any two or more of the listed elements.

Also herein, all numbers are assumed to be modified by the term “about”and preferably by the term “exactly.” As used herein in connection witha measured quantity, the term “about” refers to that variation in themeasured quantity as would be expected by the skilled artisan making themeasurement and exercising a level of care commensurate with theobjective of the measurement and the precision of the measuringequipment used.

Also herein, the recitations of numerical ranges by endpoints includeall numbers subsumed within that range as well as the endpoints (e.g., 1to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

As used herein, the term “room temperature” refers to a temperature ofabout 20° C. to about 25° C. or about 22° C. to about 25° C.

The above summary of the present disclosure is not intended to describeeach disclosed embodiment or every implementation of the presentdisclosure. The description that follows more particularly exemplifiesillustrative embodiments. In several places throughout the application,guidance is provided through lists of examples, which examples can beused in various combinations. In each instance, the recited list servesonly as a representative group and should not be interpreted as anexclusive list.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The present disclosure provides fibers (e.g., fibers for use in makingwipes such as wet wipes), and methods of making the fibers. The wetwipes can be used as cleaning or disinfecting wipes (e.g., antimicrobialwipes such as antiviral and/or antibacterial and/or antifungal wipes).Significantly, the wet wipes of the disclosure have advantageous “shelflife” stability.

Fibers of the present disclosure include an aliphatic polyester, anepoxidized fatty ester, and an optional shrink reduction additive. Inone embodiment, the present disclosure provides a fiber that includes: acore including an aliphatic polyester; and an epoxidized fatty esterhaving greater than 4.7 wt-% oxirane oxygen, based on the total weightof the epoxidized fatty ester; wherein the epoxidized fatty ester isdisposed on the surface of the fiber core in an amount of at least 0.5wt-%, based on the total weight of the fiber (i.e., dry weight of thefibers including the core and the epoxidized fatty ester and anyoptional additives disposed on the fiber core, after removal or thewater or any solvents used to apply the epoxidized fatty ester).

Herein, “disposed on” means that the epoxidized fatty ester is coatedon, deposited on, or loaded on, the fiber surface. Thus, the epoxidizedfatty ester is not reacted with or blended with the aliphatic polyesteror otherwise dispersed throughout the thickness of the fiber core.

In certain embodiments the epoxidized fatty ester is pre-coated onto thefibers including an aliphatic polyester prior to contact with an aqueouscomposition that includes water and a surfactant and/or a biocide.

In certain embodiments, the epoxidized fatty ester is included in theaqueous composition that includes water and a surfactant and/or abiocide and is disposed onto the surface of the fibers including analiphatic polyester when the fibers come into contact with the aqueouscomposition.

Generally, the epoxidized fatty ester and the aliphatic polyester arenot noticeably reacted with each other such that chemical bonds areformed. That is, relative to the aliphatic polyester, the epoxidizedfatty ester is “unreacted.”

Herein, an unreacted epoxidized fatty ester is one that does notnoticeably react with the aliphatic polyester during normal thermalprocessing and does not noticeably increase the molecular weight of thealiphatic polyester or the corresponding viscosity of the aliphaticpolyester. In this context, an “unreacted” epoxidized fatty ester is onethat remains in a “free” or unreacted state when disposed on fiber ofthe aliphatic polyester in an amount of at least 80%, or at least 90%,or at least 95%, of the unreacted epoxidized fatty ester based on theanalysis by Gel Permeation Chromatography (GPC) of the fiber.

Thus, the present disclosure provides a process for improving thehydrolytic stability of fibers that include an aliphatic polyester. Incertain embodiments, the method includes: forming fibers including analiphatic polyester; and depositing an epoxidized fatty ester on thesurface of the fibers in an amount of at least 0.5 wt-%, based on thetotal weight of fibers (including the core and the epoxidized fattyester and optional additives disposed on the core); wherein theepoxidized fatty ester has at least 4.7 wt-% oxirane oxygen, based onthe total weight of the epoxidized fatty ester.

Fibers can be made by various techniques, including but not limited to,co-extrusion, solvent-based methods, and melt processing techniques suchas melt-blown and spunbond processes.

In certain embodiments, the fibers are continuous fibers that form a web(i.e., a network of entangled fibers forming a sheet like or fabric likestructure), particularly a nonwoven web (i.e., an assembly of polymericfibers (oriented in one direction or in a random manner) held togetherby mechanical interlocking, fusing of thermoplastic fibers, bonding witha suitable binder such as a natural or synthetic polymeric resin, or acombination thereof).

Webs made from the fibers can be woven, nonwoven, or knitted webs. Thefibers can include fibers of indefinite length (e.g., filaments), fibersof discrete length (e.g., staple fibers), and multifilament yarns.Suitable manufacturing processes for making nonwoven webs include, butare not limited to, carding, meltblown, wet laid, air laid, or spunbond.The nonwoven webs may be post processed into other forms. For example,they may be thermal bonded, hydroentangled, needlepunched, embossed,apertured, perforated, microcreped, laminated, etc. in order to provideadditional properties. The webs can be single layer or multi-layerconstructions, such as SMS (Spunbond, Meltblown, Spunbond) or SMMS webs.

The general methods of making spunbond nonwoven fabric are well known inthe art. An exemplary process of making spunbond nonwoven webs isdescribed in U.S. Pat. No. 7,470,389 (Berrigan et al.). Generally, astream of filaments is extruded from a spin-pack having multipleorifices arranged in a regular pattern and directed through a processingchamber. The stream of filaments are subsequently cooled and stretchedwith high speed air jets and deposited onto a collecting belt in arandom manner. The collecting belt is generally porous. A vacuum devicecan be positioned below the collecting belt to assist the fiberdeposition onto the collecting belt. The collected mass (web) can beimparted strength and integrity by thermal bonding (e.g., applyingheated rolls or passing hot air through) to partially melt the polymerand fuse the fibers together. The web can be further bonded to improvestrength and other properties by mechanical bonding processes such ashydroentangling as described, for example, in U.S. Pat. No. 4,808,467(Israel et al.).

In certain embodiments, the fibers made using compositions of thepresent disclosure are fine fibers, wherein a population of such fibershas a median fiber diameter of no greater than 50 μm, or no greater than25 μm, or no greater than 20 μm, or no greater than 10 μm, or no greaterthan 5 μm. In certain embodiments, the fibers are microfibers, wherein apopulation of such fibers has a median fiber diameter of at least one μmbut no greater than 100 μm. In certain embodiments, the fibers areultrafine microfibers, wherein a population of such fibers has a medianfiber diameter of two μm or less. In certain embodiments, the fibers aresub-micrometer fibers, wherein a population of such fibers has a medianfiber diameter of no greater than one μm.

Once made, the fibers, or more typically a web of the fibers, anepoxidized fatty ester can be disposed thereon either by depositing theepoxidized fatty ester on the surface of the fibers (or more typically,a web of the fibers) by techniques such as spraying, dipping, and/orsoaking, and optionally drying. Typically, an amount of at least 0.5wt-%, based on the total weight of the fibers, of an epoxidized fattyester is deposited on the fibers, wherein the amount is based on the dryweight of the fibers (including the core and the epoxidized fatty esterand any optional additives disposed on the fiber core, after removal orthe water or any solvents used to apply the epoxidized fatty ester).Alternatively, the fibers can be provided in a useable form, e.g., in afibrous web, and combined with an aqueous composition that includes anepoxidized fatty ester in an amount of at least 0.5 wt-%, based on thetotal weight of the aqueous composition. The aqueous composition canalso include a surfactant and/or a biocide (dissolved or dispersed inthe water) as is provided, for example, in commercial cleaning and/ordisinfecting compositions. The aqueous composition may also include oneor more organic solvents, such as alcohols (e.g., isopropanol), alongwith the water.

The addition of an epoxidized fatty ester additive to the surface of analiphatic polyester fiber improves the hydrolytic stability of thealiphatic polyester fibers, and hence, the “shelf life” of the fibers.

An improvement in the hydrolytic stability of fibers that include analiphatic polyester can be demonstrated by an improvement in the tensilestrength of the fibers forming a web, and optionally the dimensionalstability (e.g., if a shrink reduction additive is used), of the fibersforming a web, particularly after aging in an aqueous medium.

Typically, improvement in tensile strength means that a web made offibers of the present disclosure demonstrates greater than 10% increasein tensile strength after aging at a temperature of 135° F. for at least25 days (in an aqueous cleaning and/or disinfecting solution asexemplified in the Examples Section), compared to a web made of fibersof the same aliphatic polyester without such additives.

Typically, improvement in dimensional stability means that a web made offibers of the present disclosure has at least one dimension whichshrinks by no greater than 10% (preferably, no greater than 5%) in theplane of the web when the web is heated to a temperature above a glasstransition temperature of the fibers, but below the melting point of thefibers in an unrestrained (i.e., free to move) condition, as compared toa web made of fibers of the same aliphatic polyester without suchadditives.

In certain situations, compositions of the present disclosure may haveshrinkage problems since epoxidized fatty esters, such as epoxidizedvegetable oils, are well known as plasticizers that can significantlyreduce the crystallinity of an aliphatic polyester. The addition of anoptional shrinkage reduction additive in combination with the aliphaticpolyester in the fiber core can thus provide a reduction in shrinkage.Typically, reduction in shrinkage means a demonstration of greater than5% decrease in shrinkage compared to a web made of fibers of the samealiphatic polyester and epoxidized fatty ester combination without suchshrink reduction additive.

Aliphatic Polyesters

Aliphatic polyesters useful in embodiments of the present disclosureinclude homo- and co-polymers of poly(hydroxyalkanoates), and homo- andco-polymers of those aliphatic polyesters derived from the reactionproduct of one or more polyols with one or more polycarboxylic acidsthat is typically formed from the reaction product of one or morealkanediols with one or more alkanedicarboxylic acids (or acylderivatives). Aliphatic polyesters may further be derived frommultifunctional polyols, e.g. glycerin, sorbitol, pentaerythritol, andcombinations thereof, to form branched, star, and graft homo- andco-polymers.

Exemplary aliphatic polyesters are poly(lactic acid), poly(glycolicacid), poly(lactic-co-glycolic acid), polybutylene succinate,polyethylene adipate, polyhydroxybutyrate, polyhydroxyvalerate, blends,and copolymers thereof. One particularly useful class of aliphaticpolyesters are poly(hydroxyalkanoates), derived by condensation orring-opening polymerization of hydroxy acids, or derivatives thereof.Suitable poly(hydroxyalkanoates) may be represented by the Formula (I):H(O—R—C(O)—)_(a)OH   (I)wherein: R is an alkylene moiety that may be linear or branched having 1to 20 carbon atoms, preferably having 1 to 12 carbon atoms, morepreferably having 1 to 6 carbon atoms; and n is a number such that theester is polymeric, and is preferably a number such that the molecularweight of the aliphatic polyester is at least 8,000 daltons (Da).

In Formula (I), R may further include one or more catenary (i.e., inchain) ether oxygen atoms. That is, R may optionally be substituted bycatenary (bonded to carbon atoms in a carbon chain) oxygen atoms.Generally, the R group of the hydroxy acid is such that the pendanthydroxyl group is a primary or secondary hydroxyl group.

Useful poly(hydroxyalkanoates) include, for example, homo- andcopolymers of poly(3-hydroxybutyrate), poly(4-hydroxybutyrate),poly(3-hydroxyvalerate), poly(lactic acid) (as known as polylactide),poly(3-hydroxypropanoate), poly(4-hydroxypentanoate),poly(3-hydroxypentanoate), poly(3-hydroxyhexanoate),poly(3-hydroxyheptanoate), poly(3-hydroxyoctanoate), polydioxanone,polycaprolactone, and polyglycolic acid (i.e., polyglycolide).

Copolymers of two or more of the above hydroxy acids may also be used,for example, poly(3-hydroxybutyrate-co-3-hydroxyvalerate),poly(lactate-co-3-hydroxypropanoate), poly(glycolide-co-dioxanone), andpoly(lactic acid-co-glycolic acid).

Blends of two or more of the poly(hydroxyalkanoates) may also be used,as well as blends (miscible or immiscible) with one or more otherpolymers and/or copolymers.

Aliphatic polyesters useful in the disclosure may include homopolymers,random copolymers, block copolymers, star-branched random copolymers,star-branched block copolymers, dendritic copolymers, hyperbranchedcopolymers, graft copolymers, and combinations thereof.

Another useful class of aliphatic polyesters includes those aliphaticpolyesters derived from the reaction product of one or more alkanediolswith one or more alkanedicarboxylic acids (or acyl derivatives). Suchpolyesters have the general Formula (II):HO(—C(O)—R″—C(O)—)_(n)—[OR′O—C(O)—R″—C(O)—O]_(m).(R′O)_(n)H   (II)wherein: R′ and R″ each represent an alkylene moiety that may be linearor branched having from 1 to 20 carbon atoms, preferably 1 to 12 carbonatoms; m is a number such that the ester is polymeric, and is preferablya number such that the molecular weight of the aliphatic polyester is atleast 8,000 daltons (Da); and each n is independently 0 or 1.

In Formula (II), R′ and R″ may further include one or more catemary(i.e., in chain) ether oxygen atoms. Examples of aliphatic polyestersinclude those homo- and co-polymers derived from (a) one or more of thefollowing diacids (or derivative thereof): succinic acid; adipic acid;1,12 dicarboxydodecane; fumaric acid; glutartic acid; diglycolic acid;and maleic acid; and (b) one of more of the following diols: ethyleneglycol; 30 polyethylene glycol; 1,2-propane diol; 1,3-propanediol;1,2-propanediol; 1,2-butanediol; 1,3-butanediol; 1,4-butanediol;2,3-butanediol; 1,6-hexanediol; 1,2-alkane diols having 5 to 12 carbonatoms; diethylene glycol; polyethylene glycols having a molecular weightof 300 to 10,000 daltons, preferably 400 to 8,000 daltons; propyleneglycols having a molecular weight of 300 to 4000 daltons; block orrandom copolymers derived from ethylene oxide, propylene oxide, orbutylene oxide; dipropylene glycol; and polypropylene glycol, and (c)optionally a small amount (i.e., 0.5-7.0 mole-%) of a polyol with afunctionality greater than two such as glycerol, neopentyl glycol, andpentaerythritol. Such polymers may include polybutylene succinatehomopolymer, polybutylene adipate homopolymer, polybutyleneadipate-succinate copolymer, polyethylene succinate-adipate copolymer,polyethylene glycol succinate homopolymer and polyethylene adipatehomopolymer.

Commercially available aliphatic polyesters include poly(lactide),poly(glycolide), poly(lactide-co-glycolide),poly(L-lactide-co-trimethylene carbonate), poly(dioxanone),poly(butylene succinate), and poly(butylene adipate).

Preferred aliphatic polyesters include those derived fromsemicrystalline polylactic acid. Poly(lactic acid) or polylactide haslactic acid as its principle degradation product, which is commonlyfound in nature, is non-toxic and is widely used in the food,pharmaceutical and medical industries. The polymer may be prepared byring-opening polymerization of the lactic acid dimer, lactide. Lacticacid is optically active and the dimer appears in four different forms:L,L-lactide, D,D-lactide, D,L-lactide (meso lactide) and a racemicmixture of L,L- and D,D-. By polymerizing these lactides as purecompounds or as blends, poly(lactide) polymers may be obtained havingdifferent stereochemistries and different physical properties, includingcrystallinity. The L,L- or D,D-lactide yields semicrystallinepoly(lactide), while the poly(lactide) derived from the D,L-lactide isamorphous. The polylactide preferably has a high enantiomeric ratio tomaximize the intrinsic crystallinity of the polymer. The degree ofcrystallinity of a poly(lactic acid) is based on the regularity of thepolymer backbone and the ability to crystallize with other polymerchains. If relatively small amounts of one enantiomer (such as D-) iscopolymerized with the opposite enantiomer (such as L-) the polymerchain becomes irregularly shaped, and becomes less crystalline. Forthese reasons, when crystallinity is favored, it is desirable to have apoly(lactic acid) that is at least 85% of one isomer, more preferably atleast 90% of one isomer, or even more preferably at least 95% of oneisomer in order to maximize the crystallinity. An approximatelyequimolar blend of D-polylactide and L-polylactide is also useful. Thisblend forms a unique crystal structure having a higher melting point(approximately 210° C.) than does either the D-poly(lactide) andL-poly(lactide) alone (approximately 160° C.), and has improved thermalstability, see H. Tsuji et al., Polymer, 40 (1999) 6699-6708.

Copolymers, including block and random copolymers, of poly(lactic acid)with other aliphatic polyesters may also be used. Useful co-monomersinclude glycolide, beta-propiolactone, tetramethylglycolide,beta-butyrolactone, gamma-butyrolactone, pivalolactone, 2-hydroxybutyricacid, alpha-hydroxyisobutyric acid, alpha-hydroxyvaleric acid,alpha-hydroxyisovaleric acid, alpha-hydroxycaproic acid,alpha-hydroxyethylbutyric acid, alpha-hydroxyisocaproic acid,alpha-hydroxy-betamethylvaleric acid, alpha-hydroxyoctanoic acid,alpha-hydroxydecanoic acid, alpha-hydroxymyristic acid, andalpha-hydroxystearic acid. Blends of poly(lactic acid) and one or moreother aliphatic polyesters, or one or more other polymers may also beused. Examples of useful blends include poly(lactic acid) with a secondpolymer selected from poly(vinyl alcohol), polyethylene glycol,polysuccinate, polyethylene oxide, polycaprolactone and polyglycolide.

Poly(lactide)s may be prepared as described in U.S. Pat. No. 6,111,060(Gruber, et al.), U.S. Pat. No. 5,997,568 (Liu), U.S. Pat. No. 4,744,365(Kaplan et al.), U.S. Pat. No. 5,475,063 (Kaplan et al.), U.S. Pat. No.6,143,863 (Gruber et al.), U.S. Pat. No. 6,093,792 (Gross et al.), U.S.Pat. No. 6,075,118 (Wang et al.), U.S. Pat. No. 5,952,433 (Wang et al.),U.S. Pat. No. 6,117,928 (Hiltunen et al.), U.S. Pat. No. 5,883,199(McCarthy et al.), and International Publication Nos. WO 98/124951 (Tsaiet al.), WO 00/112606 (Tsai et al.), WO 84/04311 (Lin), WO 99/50345(Kolstad et al.), WO 99/06456 (Wang et al.), WO 94/07949 (Gruber etal.), WO 96/122330 (Randall et al.), and WO 98/50611 (Ryan et al.), forexample. Reference may also be made to J. W. Leenslag et al., J. Appl.Polymer Science, vol. 29 (1984), pp 2829-2842, and H. R. Kricheldorf,Chemosphere, vol. 43 (2001) 49-54.

The molecular weight of the polymer should be chosen so that the polymermay be processed as a melt. By “melt-processible,” it is meant that thealiphatic polyesters are fluid or can be pumped or extruded at thetemperatures used to process the fibers, and do not degrade or gel atthose temperatures to the extent that the physical properties are sopoor as to be unusable for the intended application. Thus, many of thematerials can be made into nonwovens using melt processes such as spunbond, blown microfiber, and the like. Certain embodiments also may beinjection molded.

In certain embodiments, the molecular weight (number average) ofsuitable aliphatic polyesters is at least 8,000, or at least 10,000, orat least 30,000, or at least 50,000 daltons. Although higher molecularweight polymers generally yield films with better mechanical properties,for both melt processed and solvent cast polymers excessive viscosity istypically undesirable. The molecular weight of the aliphatic polyesteris typically no greater than 1,000,000, preferably no greater than500,000, and most preferably no greater than 300,000 daltons (Da), asmeasured by gel permeation chromatography (GPC).

For a poly(lactide), for example, the molecular weight may be from 8,000to 1,000,000 daltons, and is preferably from 30,000 to 300,000 daltons(Da).

The aliphatic polyester may be blended with other polymers but typicallyis present in fibers of the present disclosure in an amount of at least50 weight percent, or at least 60 weight percent, or at least 65 weightpercent, or at least 80 weight percent (wt-%) of the fibers of thepresent disclosure.

Epoxidized Fatty Esters

Epoxidized fatty esters, such as epoxidized vegetable oils, are commonlyknown as plasticizers for easy thermal processing of polymers (orprocessing aides). Suitable epoxidized fatty esters for use on fibers ofthe present disclosure are used as hydrolysis stabilizing agents. Thatis, suitable epoxidized fatty esters are those capable of improving thehydrolytic stability of fibers that include an aliphatic polyester uponbeing disposed on the fibers. Typically, because such deposition (e.g.,coating) does not involve thermal processing, the epoxidized fatty esteris unreacted relative to the aliphatic polyester.

Even though there is little or no reaction (e.g., crosslinking) betweenthe aliphatic polyester and the epoxidized fatty ester, the presence ofthe free (i.e., unreacted) epoxidized fatty esters in the presence ofthe aliphatic polyester reduces the hydrolysis rate when the aliphaticpolyester is aged or dispersed into a water-based medium for a longperiod of time.

It is believed that as the aliphatic polyester starts to hydrolyze in anaqueous environment, more carboxylic acid groups are formed in thealiphatic polyester that results in an increase in acidity (lower pH).As the hydrolysis continues, the epoxy group of the epoxidized fattyester tends to react with the carboxylic acid group of the aliphaticpolyester. As such, the epoxidized fatty ester acts as a crosslinker forthe hydrolyzable aliphatic polyester, which results in the formation ofa higher molecular weight polymer network. At the same time, thereaction that occurs between the epoxy groups of epoxidized fatty esterand the carboxylic acid groups of the aliphatic polyester that areformed during hydrolysis actually neutralizes the pH of the aliphaticpolyester. This results in a slowdown of the hydrolysis of the aliphaticpolyester that correspondingly leads to an increased shelf life of thealiphatic polyester in aqueous media. From this aforementioned theory,it is suggested that a higher oxirane oxygen of the epoxidized fattyester will tend to greatly increase the hydrolytic stability of analiphatic polyester such as poly(lactic acid).

Fibers of the present disclosure typically have disposed thereon anepoxidized fatty ester that has greater than 4.7 wt-% oxirane oxygen,based on the total weight of the epoxidized fatty ester. In certainembodiments, the amount of oxirane oxygen is at least 5.5 wt-%, at least6 wt-%, or at least 9 wt-%, oxirane oxygen, based on the total weight ofthe epoxidized fatty ester. In certain embodiments, the amount ofoxirane oxygen is up to 23 wt-%, or up to 11 wt-%, oxirane oxygen, basedon the total weight of the epoxidized fatty ester. In certainembodiments, the amount of oxirane oxygen is 6 wt-% to 11 wt-% oxiraneoxygen, based on the total weight of the epoxidized fatty ester.

In certain embodiments, the epoxidized fatty ester is an epoxidizedpoly(fatty ester) (i.e., a di- or tri-ester or higher functional ester).In certain embodiments, the epoxidized vegetable oil includes adi-ester, tri-ester, or combinations thereof. In certain embodiments,the epoxidized vegetable oil includes a tri-ester or higher functionalester.

In certain embodiments, the epoxidized fatty ester is a triglyceride ofan epoxidized polyunsaturated fatty acid. The epoxidized polyunsaturatedfatty acid can be made from the epoxidation of a triglyceride of apolyunsaturated fatty acid, wherein the triglyceride of apolyunsaturated fatty acid can be made from the estification of glyceroland a polyunsaturated fatty acid. Preferrably, the polyunsaturated fattyacid has two or more unsaturated double bonds for higher amounts ofoxirane oxygen resulting from an epoxidization process. In certainembodiments, the polyunsaturated fatty acid is selected from linoleicacid, linoelaidic acid, α-linolenic acid, arachidonic acid,eicosapentaenoic acid, docosahexaenoic acid, and combinations thereof.The chemical structures of such preferred polyunsaturated fatty acidsare shown in the following table.

Common name Chemical structure Linoleic acidCH₃(CH₂)₄CH═CHCH₂CH═CH(CH₂)₇COOH (9E,9E) Linoelaidic acidCH₃(CH₂)₄CH═CHCH₂CH═CH(CH₂)₇COOH (9Z,9Z) α-Linolenic acidCH₃CH₂CH═CHCH₂CH═CHCH₂CH═CH(CH₂)₇COOH Arachidonic acidCH₃(CH₂)₄CH═CHCH₂CH═CHCH₂CH═CHCH₂CH═CH(CH₂)₃COOH Eicosapentaenoic acidCH₃CH₂CH═CHCH₂CH═CHCH₂CH═CHCH₂CH═CHCH₂CH═CH(CH₂)₃COOH Docosahexaenoicacid CH₃CH₂CH═CHCH₂CH═CHCH₂CH═CHCH₂CH═CHCH₂CH═CHCH₂CH═CH(CH₂)₂COOH

In certain embodiments, the epoxidized fatty ester is an epoxidizedvegetable oil. In certain embodiments, the epoxidized vegetable oil isselected from the group of epoxidized soybean oil, epoxidized cottonseedoil, epoxidized wheat germ oil, epoxidized soya oil, epoxidized cornoil, epoxidized sunflower oil, epoxidized safflower oil, epoxidized hempoil, epoxidized linseed oil, and combinations thereof.

In certain embodiments, the vegetable oil used for preparation of theepoxidized vegetable oil has a polyunsaturated value of at least 50grams per 100 grams total oil, preferably at least 60 grams per 100grams total oil. The polyunsaturated value is the weight of thepolyunsaturated oil in 100 grams of total oil (100 g of saturatedoil+monounsaturated oil+polyunsaturated oil). The polyunsaturated valuesof various oils, useful for making epoxidized vegetable oils, are shownin the following table, which shows that examples of epoxidizedvegetable oil having a polyunsaturated value of at least approximately50 grams per 100 grams total oil include wheat germ sunflower oil,safflower oil, and hemp oil.

Saturated Monounsaturated Polyunsaturated Oil g/100 g g/100 g g/100 gCottonseed oil 25.5 21.3 48.1 Wheat germ oil 18.8 15.9 60.7 Soya oil14.5 23.2 56.5 Corn oil 12.7 24.7 57.8 Sunflower oil 11.9 20.2 63.0Safflower oil 10.2 12.6 72.1 Hemp oil 10 15 75

In certain embodiments, fibers of the present disclosure typicallyinclude at least 1 wt-%, or at least 2 wt-%, or at least 3 wt-%, or atleast 5 wt-%, of an epoxidized fatty ester, based on the total weight ofthe fibers (i.e., dry weight of the fibers including the core and theepoxidized fatty ester and any optional additives disposed on the fibercore, after removal or the water or any solvents used to apply theepoxidized fatty ester). In certain embodiments, fibers of the presentdisclosure typically include up to 20 wt-%, or up to 10 wt-%, of anepoxidized fatty ester, based on the total weight of the fibers (i.e.,dry weight of the fibers including the core and the epoxidized fattyester and any optional additives disposed on the fiber core, afterremoval or the water or any solvents used to apply the epoxidized fattyester). In certain embodiments, fibers of the present disclosuretypically include up to 7 wt-% (and in some embodiments, less than 7wt-%), or up to 6 wt-%, of an epoxidized fatty ester, based on the totalweight of the fibers (i.e., dry weight of the fibers including the coreand the epoxidized fatty ester and any optional additives disposed onthe fiber core, after removal or the water or any solvents used to applythe epoxidized fatty ester).

Optional Shrink Reduction Additives

The “shrink reduction” or “antishrink” or “antishrinkage” additive(i.e., agent) refers to a thermoplastic polymeric additive which, whenadded to the aliphatic polyester in a suitable amount during thermalprocess formation of a uniform fibrous web, results in a web having atleast one dimension which shrinks by no greater than 10% in the plane ofthe web when the web is heated to a temperature above a glass transitiontemperature of the fibers, but below the melting point of the fibers inan unrestrained (free to move) state, when compared to a web made in thesame way with the same components without the shrink reduction additive.Although, typically, because the epoxidized fatty acid is disposed onthe surface of the aliphatic polyester fibers, as opposed to mixedwithin the aliphatic polyester, there is often no need for the shrinkreduction additive.

Preferred shrink reduction additives (i.e., shrink reduction agents)form a dispersed phase in the aliphatic polyester when a mixture iscooled to 23-25° C. Preferred shrink reduction additives are alsosemicrystalline thermoplastic polymers as determined by differentialscanning calorimetry.

Potentially useful semicrystalline polymers include polyethylene, linearlow density polyethylene, polypropylene, polyoxymethylene,poly(vinylidine fluoride), poly(methyl pentene),poly(ethylene-chlorotrifluoroethylene), poly(vinyl fluoride),poly(ethylene oxide) (PEO), poly(ethylene terephthalate), poly(butyleneterephthalate), semicrystalline aliphatic polyesters includingpolycaprolactone (PCL), aliphatic polyamides such as nylon 6 and nylon66, thermotropic liquid crystal polymers, and combinations thereof.Particularly preferred semicreystalline polymers include polypropylene,nylon 6, nylon 66, polycaprolactone, and poly(ethylene oxide).

The shrink reduction additives have been shown to dramatically reducethe shrinkage of PLA nonwovens. The molecular weight (MW) of theseadditives may affect the ability to promote shrinkage reduction.Preferably the MW is greater than about 10,000 daltons, preferablygreater than 20,000 daltons, more preferably greater than 40,000 daltonsand most preferably greater than 50,000 daltons.

Derivatives of the thermoplastic shrink reduction polymers also may besuitable. Preferred derivatives will likely retain some degree ofcrystallinity. For example, polymers with reactive end groups such asPCL and PEO can be reacted to form, for example, polyesters orpolyurethanes, thus increasing the average molecular weight.

A highly preferred shrink reduction additive is a polyolefin, inparticular a polypropylene. Polypropylene homo- and co-polymers usefulin practicing embodiments of the present disclosure may be selected frompolypropylene homopolymers, polypropylene copolymers, and blends thereof(collectively polypropylene polymers). The homopolymers may be atacticpolypropylene, isotactic polypropylene, syndiotactic polypropylene andblends thereof. The copolymer can be a random copolymer, a statisticalcopolymer, a block copolymer, and blends thereof. In particular, thepolymer blends described herein include impact copolymers, elastomersand plastomers, any of which may be physical blends or in situ blendswith the polypropylene.

The polypropylene polymers can be made by any method known in the artsuch as by slurry, solution, gas phase or other suitable processes, andby using catalyst systems appropriate for the polymerization ofpolyolefins, such as Ziegler-Natta-type catalysts, metallocene-typecatalysts, other appropriate catalyst systems or combinations thereof.In a preferred embodiment, the propylene polymers are made by thecatalysts, activators and processes described in U.S. Pat. No. 6,342,566(Burkhardt et al.); U.S. Pat. No. 6,384,142 (Burkhardt et al.); WO03/040201 (Stevens et al.); WO 97/19991 (McAlpin et al.) and U.S. Pat.No. 5,741,563 (Mehta et al.). Likewise, the polypropylene polymers maybe prepared by the process described in U.S. Pat. Nos. 6,342,566 and6,384,142. Such catalysts are well known in the art, and are describedin, for example, ZIEGLER CATALYSTS (Gerhard Fink, Rolf Mulhaupt and HansH. Brintzinger, eds., Springer-Verlag 1995); Resconi et ai., Selectivityin Propene Polymerization with Metallocene Catalysts, 100 CHEM. REV. 201253-1345 (2000); and I, II METALLOCENE-BASED POLYOLEFINS (Wiley & Sons2000).

Propylene polymers that are useful in practicing some embodiments of thepresent disclosure include those sold under the tradenames ACHIEVE andESCORENE by Exxon-Mobil Chemical Company (Houston, Tex.), and variouspropylene (co)polymers sold by Total Petrochemicals (Houston, Tex.).

Presently preferred propylene homopolymers and copolymers useful in thepresent disclosure typically have: 1) a weight average molecular weight(Mw) of at least 30,000 Da, preferably at least 50,000 Da, morepreferably at least 90,000 Da, as measured by gel permeationchromatography (GPC), and/or no more than 2,000,000 30 Da, preferably nomore than 1,000,000 Da, more preferably no more than 500,000 Da, asmeasured by gel permeation chromatography (GPC); and/or 2) apolydispersity (defined as Mw/Mn, wherein Mn is the number averagemolecular weight determined by GPC) of 1, preferably 1.6, and morepreferably 1.8, and/or no more than 40, preferably no more than 20, morepreferably no more than 10, and even more preferably no more than 3;and/or 3) a melting temperature Tm (second melt) of at least 30° C.,preferably at least 50° C., and more preferably at least 60° C. asmeasured by using differential scanning calorimetry (DSC), and/or nomore than 200° C., preferably no more than 185° C., more preferably nomore than 175° C., and even more preferably no more than 170° C. asmeasured by using differential scanning calorimetry (DSC); and/or acrystallinity of at least 5%, preferably at least 10%, more preferablyat least 20% as measured using DSC, and/or no more than 80%, preferablyno more than 70%, more preferably no more than 60% as measured usingDSC; and/or 5) a glass transition temperature (Tg) of at least −40° C.,preferably at least −10° C., more preferably at least −10° C., asmeasured by dynamic mechanical thermal analysis (DMTA), and/or no morethan 20° C., preferably no more than 10° C., more preferably no morethan 5° C., as measured by dynamic mechanical thermal analysis (DMTA);and/or 6) a heat of fusion (Rf) of 180 J/g or less, preferably 150 J/gor less, more preferably 120 J/g or less as measured by DSC and/or atleast 20 J/g, more preferably at least 40 J/g as measured by DSC; and/or7) a crystallization temperature (Tc) of at least 15° C., preferably atleast 20° C., more preferably at least 25° C., even more preferably atleast 60° C. and/or, no more than 120° C., preferably no more than 115°C., more preferably no more than 110° C., even more preferably no morethan 145° C.

Although typically not necessary, fibers of the present disclosure canoptionally include a shrink reduction additive (preferably a propylenepolymer (including both poly(propylene) homopolymers and copolymers)) inan amount of up to 10 wt-%. In certain embodiments, fibers of thepresent disclosure include a shrink reduction additive in an amount ofat least 0.5 wt-%, or at least 1 wt-%, or at least 2 wt-% by weight,based on the total weight of the fibers. In certain embodiments, fibersof the present disclosure include a shrink reduction additive(preferably a propylene polymer (including both poly(propylene)homopolymers and copolymers)) in an amount of up to 5 wt-%, based on thetotal weight of the fibers.

Optional Additives

Various optional additives may be added to the fibers of the presentdisclosure, either in the core or disposed on the surface of the fibers.Suitable additives include, but are not limited to, particulates,fillers, stabilizers, plasticizers, tackifiers, flow control agents,cure rate retarders, adhesion promoters (for example, silanes andtitanates), adjuvants, impact modifiers, expandable microspheres,thermally conductive particles, electrically conductive particles,silica, glass, clay, talc, pigments, colorants, glass beads or bubbles,antioxidants, optical brighteners, antimicrobial agents, surfactants,wetting agents, fire retardants, and repellents such as hydrocarbonwaxes, silicones, and fluorochemicals. However, some fillers (i.e.,insoluble organic or inorganic materials generally added to augmentweight, size or to fill space in the resin for example to decrease costor impart other properties such as density, color, impart texture,effect degradation rate and the like) may detrimentally effect fiberproperties.

Fillers, if used, can be particulate non-thermoplastic or thermoplasticmaterials. Fillers also may be non-aliphatic polyesters polymers whichoften are chosen due to low cost such as starch, lignin, and cellulosebased polymers, natural rubber, and the like. These filler polymers tendto have little or no crystallinity.

Fillers, plasticizers, and other additives, when used at levels above 3%by weight, and more certainly above 5% by weight of the aliphaticpolyester, can have a significant negative effect on physical propertiessuch as tensile strength of a web of the fibers (e.g., a nonwoven web).Above 10% by weight of the aliphatic polyester resin, these optionaladditives can have a dramatic negative effect on physical properties.Therefore, total optional additives are typically present at no morethan 10% by weight, preferably no more than 5% by weight and mostpreferably no more than 3% by weight based on the weight of thealiphatic polyester.

Wet Wipes

Fibers of the present disclosure can be used in wipes, particularly wetwipes.

“Wet” wipe is a wipe wherein a substrate, typically a fibrous web (e.g.,nonwoven web), has been pre-moistened with the aqueous composition. Thatis, the aqueous composition is in contact with the fibrous web. In mostcases the wipe has been saturated with the aqueous composition (i.e.,full absorbent capacity of the substrate used). But this may notnecessarily have to be the case. It would depend on the absorbentcapacity of the wipe and aqueous formulation. As long as the wipe can beloaded with enough active material, it would not have to be completelysaturated. In some cases the wipes may be super saturated, i.e., havemore liquid than its absorbent capacity. This is achieved, for example,by delivering the wipes from a container with excess liquid composition.

Wet wipes are typically sold in sealed single-use or resealablemulti-use packages or canisters often with an excess of the aqueouscomposition. “Wet” wipe also includes a wipe that is coated with aconcentrate up to 100% solids that is subsequently wet with water by theuser. For example, a roll of perforated wipes can be provided in acontainer to which the user adds a predetermined amount of water thatwicks into the roll of wipes. In certain embodiments, the aqueouscomposition is present in an amount of at least 2 times, or at least 4times, the weight of the fibrous web. In certain embodiments, theaqueous composition is present in an amount of up to 6 times, the weightof the fibrous web.

Herein, a wet wipe includes: a fibrous web as described herein and anaqueous composition that includes water and a surfactant and/or abiocide (dissolved or dispersed in the water). The aqueous compositionmay also include one or more organic solvents, such as alcohols (e.g.,isopropanol), along with the water. The aqueous composition is incontact with the fibrous web.

For example, in certain embodiments, a wet wipe of the presentdisclosure includes a fibrous web that includes fibers, wherein eachfiber includes: a core comprising an aliphatic polyester; and anepoxidized fatty acid having greater than 4.7 wt-% oxirane oxygen, basedon the total weight of the epoxidized fatty ester; wherein theepoxidized fatty ester is disposed on the surface of the fiber core inan amount of at least 0.5 wt-%, based on the total weight of the fiber(i.e., dry weight of the fibers including the core and the epoxidizedfatty ester and any optional additives disposed on the fiber core, afterremoval or the water or any solvents used to apply the epoxidized fattyester).

The wet wipe also includes an aqueous composition that includes waterand a surfactant and/or a biocide. The aqueous composition can have a pHof 1 to 14. In certain embodiments, the aqueous composition includes atleast 0.01 wt-%, or at least 0.05 wt-%, surfactant and/or biocide, basedon the total weight of the aqueous composition. In certain embodiments,the aqueous composition includes up to 0.5 wt-%, surfactant and/orbiocide, based on the total weight of the aqueous composition.

In certain embodiments, the aqueous composition includes a surfactantand the wet wipe is a cleaning wipe.

In certain embodiments, the aqueous composition includes a biocide andthe wet wipe is a disinfecting wipe.

In certain embodiments, the aqueous composition includes a biocide and asurfactant, wherein the wet wipe is a cleaning/disinfecting wipe.

The surfactant can be nonionic, anionic, cationic, amphoteric (i.e.,zwitterionic), or combinations thereof. In certain embodiments, thesurfactant is a nonionic surfactant.

Exemplary anionic surfactants include: alcohol sulfates and sulfonates,alcohol phosphates and phosphonates, alkyl sulfates, alkyl ethersulfate, sulfate esters of an alkylphenoxy polyoxyethylene ethanol,alkyl monoglyceride sulfate, alkyl sulfonate, alkyl benzene sulfonate,alkyl ether sulfonate, ethoxylated alkyl sulfonate, alkyl carboxylate,alkyl ether carboxylate, alkyl alkoxy carboxylate, alkane sulfonate,alkylbenzene sulfonate, alkyl ester sulfonate, alkyl sulfate, alkylalkoxylated sulfate (e.g., sodium lauryl sulfate), alkyl carboxylate(e.g., sorbitan stearate), and sulfonated alkyl glucosides (e.g., sodiumdecylglucosides, hydroxypropyl sulfonate, sodium decylglucosideshydroxypropyl sulfonate and sodium laurylglucosides hydroxypropylsulfonate).

Exemplary zwitteronic surfactants include Betaine and sultaine (e.g.,C12-18 alkyl dimethyl betaines such as coconutbetaine), C10-C16 alkyldimethyl betaine (laurylbetaine), fattyacylamidopropylene(hydroxylpropylene)sulfobetaine,lauryldimethylcarboxymethylbetaine, cocamido propyl monosodiumphosphitaine, cocamido disodium 3-hydroxypropyl phosphobetaine, andamphoteric amine oxide (e.g., alkyl dimethyl amine oxides andalkylamidopropyl amine oxides).

Exemplary nonionic surfactants include ethoxylated alkylphenol,ethoxylated and propoxylated fatty alcohols, polyethylene glycol ethersof methyl glucose, ethoxylated esters of fatty acids, alkylpolyglucoside (e.g., capryl glucoside such as Glucopon 215UP, decylglucoside such as Glucopon 225DK, coco-glucoside such as Glucopon 425N,lauryl glucoside such as Glucopon 625UP, an aqueous solution of alkylglucosides based fatty acid alcohol C9-C11 such as APG 325N, and sodiumlaureth sulfate & lauryl glucoside & cocamidopropyl betaine such asPlantapon 611L, fatty alcohol polyglycolether (e.g., Dephypon LS54,Dehypon LT104), fatty alcohol ethoxylates (propoxylates), andethoxylated alkylphenol.

Exemplary cationic surfactants include aminoamide, quaternary ammoniumsalt, aminoamides (e.g., stearamidopropyl ethyldimonium ethosulfate,stearamidopropyl PG-dimonium chloride phosphate), and quaternaryammonium salts (e.g., cetyl ammonium chloride, lauryl ammonium chloride,and ditallow dimethyl ammonium chloride).

Various combinations of surfactants can be used if desired.

In certain embodiments, the biocide is a cationic biocides such as aquaternary ammonium salts (e.g., dodecyldimethyl benzyl ammoniumchloride, tridecyldimethyl benzyl ammonium chloride, tetradecyldimethylbenzyl ammonium chloride, pentadecyldimethyl benzyl ammonium chloride,hexadecyldimethyl benzyl ammonium chloride, (butyl)(dodecyl)dimethylammonium chloride, (hexyl)(decyl)dimethyl ammonium chloride,dioctyldimethyl ammonium chloride), polyhexamethyl biguanide (PHMB), andchlorhexidine gluconate), aldehydes (e.g., formaldehyde, glutaraldehyde,parabens), phenolic biocides (e.g., those described in U.S. Pat. No.6,113,933 (Beerse et al.), including thymol, tricosan, 0-penyl-phenol,p-chlorophenol, benzyl alcohol), essential oils (e.g., oils derived fromherbs, flowers, trees, and other plants such as thyme, lemongrass,citrus, lemons, orange, anise, clove, lavender, cedar), metal salts(e.g., aluminum, silver, zinc, copper, and those described in U.S. Pat.No. 6,113,933), and antimicrobial lipids such as a (C8-C12)saturatedfatty acid ester of a polyhydric alcohol, a (C12-C22)unsaturated fattyacid ester of a polyhydric alcohol, a (C8-C12)saturated fatty ether of apolyhydric alcohol, a (C12-C22)unsaturated fatty ether of a polyhydricalcohol, an alkoxylated derivative thereof, (C5-C12)1,2-saturatedalkanediol, and (C12-C18)1,2-unsaturated alkanediol or combinationsthereof (e.g., those described in U.S. Pub. No. 2005/0058673 (Scholz etal.)), peroxy acids (e.g., hydrogen peroxide, peracetic acid), andalcohols (e.g., ethyl alcohol, propyl alcohol).

In certain embodiments, the biocide is a compound capable of destroyingor reducing the concentration of bacteria including Staphylococcus spp.,Streptococcus spp., Escherichia spp., Enterococcus spp., Pseudomonasspp., or combinations thereof. In certain embodiments, the biocide is anantibacterial that destroys or reduces the concentration ofStaphylococcus aureus, Staphylococcus epidermidis, Escherichia coli,Pseudomonas aeruginosa, Streptococcus pyogenes, or combinations thereof.

Various combinations of biocides can be used if desired.

EXEMPLARY EMBODIMENTS

-   -   1. A fiber comprising:        -   a core comprising an aliphatic polyester; and        -   an epoxidized fatty ester having greater than 4.7 wt-%            oxirane oxygen, based on the total weight of the epoxidized            fatty ester;        -   wherein the epoxidized fatty ester is disposed on the            surface of the fiber core in an amount of at least 0.5 wt-%,            based on the total weight of the fiber.    -   2. The fiber of embodiment 1 wherein the epoxidized fatty ester        has at least 5.5 wt-% oxirane oxygen.    -   3. The fiber of embodiment 2 wherein the epoxidized fatty ester        has at least 6 wt-% oxirane oxygen.    -   4. The fiber of embodiment 3 wherein the epoxidized fatty ester        has at least 9 wt-% oxirane oxygen.    -   5. The fiber of any of embodiments 1 through 4 wherein the        epoxidized fatty ester has up to 23 wt-% oxirane oxygen.    -   6. The fiber of any of embodiments 1 through 5 wherein the        epoxidized fatty ester is an epoxidized poly(fatty ester).    -   7. The fiber of claim 6 wherein the epoxidized poly(fatty ester)        is a triglyceride of an epoxidized polyunsaturated fatty acid        derived from an unsaturated fatty acid selected from linoleic        acid, linoelaidic acid, α-linolenic acid, arachidonic acid,        eicosapentaenoic acid, docosahexaenoic acid, and combinations        thereof    -   8. The fiber of embodiment 6 wherein the epoxidized poly(fatty        ester) is an epoxidized vegetable oil.    -   9. The fiber of embodiment 8 wherein the epoxidized vegetable        oil is selected from the group of epoxidized soybean oil,        epoxidized cottonseed oil, epoxidized wheat germ oil, epoxidized        soya oil, epoxidized corn oil, epoxidized sunflower oil,        epoxidized safflower oil, epoxidized hemp oil, epoxidized        linseed oil, and combinations thereof    -   10. The fiber of embodiment 9 wherein the epoxidized vegetable        oil is derived from an unsaturated vegetable oil having a        polyunsaturated value of at least 60 grams per 100 grams total        oil.    -   11. The fiber of any of embodiments 8 through 10 wherein the        epoxidized vegetable oil comprises a di-ester, tri-ester, or        combinations thereof.    -   12. The fiber of any of embodiments 1 through 11 wherein the        epoxidized fatty ester is present on the fiber in an amount of        up to 20 wt-%, based on the total weight of the fiber.    -   13. The fiber of embodiment 12 wherein the epoxidized fatty        ester is present on the fiber in an amount of up to 10 wt-%,        based on the total weight of the fiber.    -   14. The fiber of embodiment 13 wherein the epoxidized fatty        ester is present on the fiber in an amount of up to 7 wt-%,        based on the total weight of the fiber.    -   15. The fiber of any of embodiments 1 through 14 wherein the        epoxidized fatty ester is present on the fiber in an amount of        at least 1 wt-%, based on the total weight of the fiber.    -   16. The fiber of any of embodiments 1 through 15 wherein the        aliphatic polyester is selected from the group of poly(lactide),        poly(glycolide), poly(lactide-co-glycolide),        poly(L-lactide-co-trimethylene carbonate), poly(dioxanone),        poly(butylene succinate), poly(butylene adipate), poly(ethylene        adipate), polyhydroxybutyrate, polyhydroxyvalerate, and blends        and copolymers thereof    -   17. The fiber of embodiment 16 wherein the aliphatic polyester        is a poly(lactide).    -   18. The fiber of any of embodiments 1 through 17 wherein the        aliphatic polyester has a number average molecular weight of at        least 8,000 Daltons.    -   19. The fiber of embodiment 18 wherein the aliphatic polyester        has a number average molecular weight of at least 10,000        Daltons.    -   20. The fiber of any of embodiments 18 or 19 wherein the        aliphatic polyester has a number average molecular weight of up        to 1,000,000 Daltons.    -   21. The fiber of any of embodiments 1 through 20 wherein the        aliphatic polyester is present in an amount of at least 80 wt-%,        based on the total weight of the fiber.    -   22. The fiber of any of embodiments 1 through 21 wherein the        core further comprises a shrink reduction additive.    -   23. The fiber of embodiment 22 wherein the shrink reduction        additive is a polyolefin.    -   24. A web comprising a plurality of the fibers of any of        embodiments 1 through 23.    -   25. The web of embodiment 24 which is a nonwoven web.    -   26. A wet wipe comprising:        -   a nonwoven web of embodiment 25; and        -   an aqueous composition comprising water and a surfactant            and/or a biocide (dissolved or dispersed therein), wherein            the aqueous composition contacts the nonwoven web.    -   27. A wet wipe comprising:        -   a fibrous web comprising fibers, wherein each fiber            comprises:            -   a core comprising an aliphatic polyester; and            -   an epoxidized fatty ester having greater than 4.7 wt-%                oxirane oxygen, based on the total weight of the                epoxidized fatty ester;            -   wherein the epoxidized fatty ester is disposed on the                surface of the fiber core in an amount of at least 0.5                wt-%, based on the total weight of the fiber; and        -   an aqueous composition contacting the fibrous web, the            aqueous composition comprising:            -   water; and            -   a surfactant and/or a biocide (dissolved or dispersed in                the water).    -   28. The wet wipe of embodiment 27 wherein the epoxidized fatty        ester is disposed on the surface of the fibers prior to        contacting the fibrous web with the aqueous composition.    -   29. The wet wipe of embodiment 27 wherein the aqueous        composition comprises water, a surfactant and/or a biocide, and        the epoxidized fatty ester, and upon contacting the fibrous web        with the aqueous composition, the epoxidized fatty ester is        deposited on the surface of the fibers.    -   30. A wet wipe comprising:        -   a fibrous web comprising fibers, wherein each fiber            comprises a core comprising an aliphatic polyester; and        -   an aqueous composition contacting the fibrous web, wherein            the aqueous composition comprises:            -   water;            -   a surfactant and/or a biocide (dissolved or dispersed in                the water); and            -   an epoxidized fatty ester having greater than 4.7 wt-%                oxirane oxygen, based on the total weight of the                epoxidized fatty ester;            -   wherein the epoxidized fatty ester is dispersed in the                aqueous composition in an amount of at least 0.5 wt-%,                based on the total weight of the aqueous composition.    -   31. The wet wipe of any of embodiments 26 through 30 wherein the        aqueous composition has a pH of 1 to 14.    -   32. The wet wipe of any of embodiments 26 through 31 wherein the        aqueous composition comprises at least 0.01 wt-% surfactant        and/or biocide, based on the total weight of the aqueous        composition.    -   33. The wet wipe of any of embodiments 26 through 32 wherein the        aqueous composition comprises a surfactant, wherein the wet wipe        is a cleaning wipe.    -   34. The wet wipe of embodiment 33 wherein the surfactant        comprises a nonionic surfactant.    -   35. The wet wipe of any of embodiments 26 through 32 wherein the        aqueous composition comprises a biocide, wherein the wet wipe is        a disinfecting wipe.    -   36. The wet wipe of any of embodiments 26 through 32 wherein the        aqueous composition comprises a biocide and a surfactant,        wherein the wet wipe is a cleaning/disinfecting wipe.    -   37. The wet wipe of any of embodiments 26 through 36 wherein the        aqueous composition is present in an amount of at least 2 times        the weight of the fibrous web.    -   38. A process for improving the hydrolytic stability of fibers        comprising an aliphatic polyester, the method comprising:        -   forming fibers comprising an aliphatic polyester; and        -   depositing an epoxidized fatty ester on the surface of the            fibers in an amount of at least 0.5 wt-%, based on the total            weight of the fibers;        -   wherein the epoxidized fatty ester has at least 4.7 wt-%            oxirane oxygen, based on the total weight of the epoxidized            fatty ester.    -   39. The process of embodiment 38 wherein forming fibers        comprises forming spunbond fibers.    -   40. The process of embodiment 38 or 39 wherein depositing the        epoxidized fatty ester on the surface of the fibers comprises        coating the epoxidized fatty ester onto the fibers.    -   41. The process of embodiment 38 through 40 wherein depositing        the epoxidized fatty ester on the surface of the fibers        comprises contacting the fibers with an aqueous composition,        wherein the aqueous composition comprises water, a surfactant        and/or a biocide, and the epoxidized fatty ester (and optionally        drying the fibers).    -   42. The process of any of embodiments 38 through 41 wherein the        fibers are formed into a fibrous web before depositing an        epoxidized fatty ester.    -   43. The process of embodiment 42 wherein the fibrous web is a        nonwoven web.    -   44. A process for improving the hydrolytic stability of a        fibrous web comprising fibers comprising an aliphatic polyester,        the method comprising:        -   forming a fibrous web comprising fibers comprising an            aliphatic polyester;        -   providing an aqueous composition comprising:            -   water;            -   an epoxidized fatty ester in an amount of at least 0.5                wt-%, based on the total weight of the aqueous                composition; and            -   optionally, a surfactant and/or a biocide;            -   wherein the epoxidized fatty ester has at least 4.7 wt-%                oxirane oxygen, based on the total weight of the                epoxidized fatty ester; and        -   contacting the fibrous web with the aqueous composition to            deposit the epoxidized fatty ester thereon (and optionally            drying the fibrous web).

EXAMPLES

Objects and advantages of this invention are further illustrated by thefollowing examples, but the particular materials and amounts thereofrecited in these examples, as well as other conditions and details,should not be construed to unduly limit this invention. These examplesare merely for illustrative purposes only and are not meant to belimiting on the scope of the appended claims.

Materials

NATUREWORKS PLA Polymer 6202D, (PLA), poly(lactic acid), available fromNatureWorks LLC, Minnetonka, Minn.

PARAPLEX G-60, (G-60), epoxidized soybean oil with 5.5 wt % of oxiraneoxygen, available from The HallStar Company, Chicago, Ill.

VIKOFLEX 4050, (VK-4050), is epoxidized octyl oleate monoester with aminimum oxirane oxygen content of 5.3 wt %, available from Arkema Inc.,King of Prussia, Pa.

VIKOFLEX 5075, (VK-5075), is a monomeric epoxidized propylene glycoldioleate with a minimum oxirane oxygen content of 4.4%, available fromArkema Inc., King of Prussia, Pa.

VIKOFLEX 7170, (VK-7170), epoxidized soybean oil with a minimum oxiraneoxygen content of 7.0 wt %, available from Arkema Inc., King of Prussia,Pa.

VIKOFLEX 7190, (VK-7190), epoxidized linseed oil with a minimum oxiraneoxygen content of 9.0 wt %, available from Arkema Inc., King of Prussia,Pa.

PLA Spunbond Nonwoven Web Preparation

The PLA spunbond nonwoven webs described in the Examples were generallyprepared on an experimental spunbond line using the equipment andprocessing techniques for spunbond nonwoven webs described in U.S.Patent Publication 2008/0038976. In a typical procedure, the PLA pelletswere fed from a hopper into a 2 inch (5.1 cm) single screw extruder(Davis-Standard BLUE RIBBON (DS-20®) available from Davis StandardCorporation, Pawcatuck, Conn.) at controlled rate. The extrudertemperature was 230° C. The molten resin was pumped via a gear pump intoa spin pack having rows of small orifices. The orifices, arranged in arectangular form, had a diameter of 0.014 inch (0.36 mm) and a length todiameter ratio (L/D) of 4. Fibers were formed through the spin pack andsubsequently cooled down by passing them through a quenching airchamber. The rate and extent of fiber attenuation was controlled by theattenuating pressure (AP) of the attenuator air—the higher theattenuating pressure, the faster and greater the extent of attenuation.The attenuated PLA fibers were collected as an unbonded fiber mat on aconventional screen support using vacuum assistance, and the fiber matwas then passed through a through-air bonder at a temperature of 147° C.in order to cause light autogeneous bonding between at least some of thefibers. The web was subsequently treated by a typicalhydroentangling/spunlacing process and then dried. This further bondedthe fibers in the web and provided web softness.

Method for Preparing Wet Wipes Using the PLA Spunbond Nonwoven Webs forAging Studies

The aging stability of PLA spunbond nonwoven webs was studied in threedifferent water based cleaning/disinfecting solutions:

Solution 1 (S1): an aqueous cleaning solution comprising 1 wt % GLUCOPON425N alkyl polyglycoside surfactant (available from BASF ChemicalCompany, Florham Park, N.J.), 0.02 wt % EASY WET 20 wetting agent basedon N-Octyl-2-Pyrrolidone (available from Ashland Inc., Covington, Ky.),0.01 wt % DOW CORNING 7305 silicone based antifoam emulsion (availablefrom Dow Corning Corporation, Midland, Mich.) 0.2 wt % MACKSTAT DM 55%active solution of Dimethylol-5,5-dimethylhydantoin (available fromRhodia, Cranbury, N.J.), 0.03 wt % OMACIDE IPBC 30 DPG fungicide basedon 3-Iodopropynylbutylcarbamate (available from Arch Chemicals, Atlanta,Ga.), 0.15 wt % fragrance (No. 70331 citrus fragrance, available fromBelle-Aire Fragrances, Mundelein, Ill.), and 98.59 wt % water. The pH ofthis solution was 7.0.

Solution 2 (S2): an aqueous solution of Lonza LC-75, a quaternaryammonium compound based aqueous disinfectant solution (EPA RegistrationNumber: 6836-334), available from Lonza Inc., Allendale, N.J. The LonzaLC-75 was diluted 1:75 with water to prepare Solution 2. The pH of thissolution was 10.5.

Solution 3 (S3): an aqueous disinfectant solution comprising 0.24 wt %CAPMUL 908P Propylene glycol monocaprylate (available from AbitecCorporation, Columbus, Ohio), 0.3 wt % Citric acid (available from SigmaAldrich, St. Louis, Mo.), 0.3 wt % Sorbic acid (available from SigmaAldrich, St. Louis, Mo.), 0.81 wt % Propylene glycol (available from DowChemical Company, Midland, Mich.), 0.49 wt % NAXOLATE® AS-LG-85 SodiumLauryl Sulfate (available from Nease Corporation, Blue Ash, Ohio), 0.13wt % Sodium hydroxide (20% solution, available from Sigma Aldrich, St.Louis, Mo.), and 97.73 wt % water. The pH of this solution was 4.5. ThePLA spunbond nonwoven webs were cut into 6 inch×5 inch (15.2 cm×12.7 cm)samples, and an excess of the cleaning/disinfecting solution used fortesting was loaded onto the webs (generally about 5-6 times the webweight). The wipes were then sealed in an aluminum bag and aged in anoven maintained at a temperature of either 135° F. or 158° F. (57° C. or70° C.) over a period of time as indicated in the Examples. Afterremoving the webs from the oven, excess cleaning solution was squeezedfrom the webs by passing the webs between nip rollers. The hydrolyticstability of the PLA spunbond nonwoven web with epoxidized vegetableoils additive in comparison to the untreated PLA spunbond nonwoven webswas then assessed by measuring the tensile strength and the % tensilestrength retention of the webs.

Test Method for Tensile Strength and % Retention

Tensile strength measurements were carried out using a Lloyd LF Plustensile tester (available from Lloyd Instruments, Segensworth FarehamEngland). The size of the nonwoven web samples that were tested was 1inch (2.54 cm)×3 inch (7.6 cm) (width×length), and the gap for thetensile measurement was ⅛ inch (0.32 cm). Measurements were in themachine direction (length direction of the test sample) unless indicatedotherwise, at a rate of 14 inches per minute. The tensile strength inthis experiment is defined as the maximum load when the nonwoven web isbroken with 1 kg load, and is the average measurement of 8 replicatenonwoven web samples. The % tensile strength retention (i.e., %retention) was calculated by dividing the tensile strength after agingby the initial tensile strength and multiplying by 100.

Method for Determining Epoxy Equivalent Weight (EEW) and % OxiraneOxygen Content

The epoxy equivalent weight of the samples was measured and calculatedusing titrimetry according to the following procedure. Each sample(about 0.5-0.9 milliequivalents epoxy) was weighed to the nearest 0.0001gram and was then dissolved in 50 mL chloroform in a 100 mL beaker andstirred magnetically until dissolved. A solution of 10 weight percenttetrabutylammonium iodide in acetic acid (10 mL) and acetic acid (20 mL)was added to the sample solution and stirred for approximately 15minutes. A drop of 0.1 weight percent methyl violet indicator solutionin acetic acid was then added. The mixture was titrated with a 0.1 Nsolution of perchloric acid in acetic acid to the potentiometricendpoint. The potentiometer was a Metrohm 751 Titrino with a Metrohm6.0229.010 Solvotrode electrode that was obtained from Metrom AG,Switzerland. A blank was titrated using the sample procedure without thesample aliquot. The volume for the blank titration was subtracted fromthe total titration volume from the above procedure. Samples were run intriplicate.

Calculations were performed as shown below:% Epoxy containing compound=[100 (V)(N)(Eq. Wt.)]÷[1000 (SW)]Epoxy Equivalent Weight (EEW)=[1000 (SW)]÷[(V)(N)]% oxirane content=[100×(V)×(N)×16]÷[1000 (SW)]

where V is the Volume of titrant used in milliliters, N is the Normalityof the titrant, SW is the Sample Weight in grams, and Eq. Wt. is theEquivalent Weight. The Equivalent Weight is the Molecular Weight of theepoxy containing compound in grams divided by the number of equivalentsper gram.

Example 1

A PLA spunbond nonwoven web was prepared using the method describedabove (AP was 12 psi). The dry basis weight of the web was about 60grams/meter². Wet wipes were prepared using Solution 1 (S1) havingPARAPLEX G-60, (G-60) epoxidized soybean oil added to the solution(S1:G-60=95:5). Wet wipes were also prepared using Solution 1 (S1)without any epoxidized vegetable oil additive for comparison. The wetwipes were aged at 135° F. (57° C.) and tensile strength data wasobtained as described above. The PLA wipe compositions, tensilestrength, and % retention data are provided in Table 1.

TABLE 1 Tensile Strength (kgf) - 135° F. (57° C.) aging Example 1 AgingControl 1 PLA web in S1 (days) PLA web in S1 with G-60 (95:5) 7 8.880815 9.1228 21 7.5429 23 7.7441 7.7973 30 4.9153 6.0653 32 4.7994 5.080935 2.6593 4.0574 36 2.4921 3.9551 37 3.5620 38 1.2082 2.2830 39 0.71031.7296 42 0.4127

Example 2

A PLA spunbond nonwoven web was prepared using the method describedabove (AP was 12 psi). The dry basis weight of the web was about 45grams/meter². Wet wipes were prepared using Solution 3 (S3) havingPARAPLEX G-60, (G-60) epoxidized soybean oil added to the solution(S3:G-60=95:5). Wet wipes were also prepared using Solution 3 (S3)without any epoxidized vegetable oil additive for comparison. The wetwipes were aged at 158° F. (70° C.) and tensile strength data wasobtained as described above. The PLA wipe compositions, tensilestrength, and % retention data are provided in Table 2.

TABLE 2 Tensile Strength (kgf) - 158° F. (70° C.) aging Example 2 AgingControl 2 PLA web in S3 (days) PLA web in S3 with G-60 (95:5) 1 6.79976.5470 2 5.2716 5.4570 3 3.3413 4.1389 4 1.9852 2.9345 5 0.4683 1.3041 60.3643

Example 3

A PLA spunbond nonwoven web was prepared using the method describedabove (AP was 12 psi). The dry basis weight of the web was about 45grams/meter². Instead of hydroentangling the web, the web was calendared(approximately 10% bond area). Wet wipes were prepared using Solution 3(S3) having PARAPLEX G-60, (G-60) epoxidized soybean oil added to thesolution (S3:G-60=95:5). Wet wipes were also prepared using Solution 3(S3) without any epoxidized vegetable oil additive for comparison. Thewet wipes were aged at 135° F. (57° C.) and tensile strength and %retention data were obtained as described above. The PLA wipecompositions, tensile strength, and % retention data are provided inTable 3.

TABLE 3 Tensile Strength (kgf) and % Retention - 135° F. (57° C.) agingExample Control 3 3 Calendared PLA Calendared PLA web in web in S3 S3with G-60 (95:5) Aging Tensile % Tensile % (days) Strength RetentionStrength Retention 0 4.75 100 4.75 100 3 4.28 90 5.32 112 6 3.81 80 4.82101 9 2.16 46 4.30 91 12 0.00 0 4.09 86 14 3.51 74 16 2.11 44 20 0.14 3

Examples 4-9

PLA spunbond nonwoven webs were prepared using the method describedabove (AP was 12 psi). The dry basis weight of the webs was about 60grams/meter². Wet wipes were prepared using Solution 1 (S1) thatincluded epoxidized vegetable oils added in to the solution. Varyingtypes and amounts of epoxidized vegetable oils were used to prepare thewet wipes and the epoxidized oils used also had different wt % oxiraneoxygen content. Wet wipes were also prepared using Solution 1 (S1)without any epoxidized vegetable oil additive for comparison. The wetwipes were aged at 158° F. (70° C.) and tensile strength and % retentiondata were obtained as described above. The PLA wipe compositions,tensile strength, and % retention data are provided in Tables 4 and 5.

TABLE 4 Tensile Strength (kgf) - 158° F. (70° C.) aging 4 5 6 7 8 9 PLAweb PLA web PLA web PLA web PLA web PLA web in S1 in S1 in S1 in S1 inS1 in S1 Example Control 4 with with with with with with Aging PLA webVK-4050 VK-5075 VK-7170 VK-7190 VK-7190 VK-7190 (days) in S1 (95:5)(95:5) (95:5) (99:1) (95:5) (90:10) 0 8.2331 8.2331 8.2331 8.2331 8.23318.2331 8.2331 1 5.9194 6.9075 5.7313 6.6936 5.6329 5.6095 6.9027 26.3704 6.7115 6.8698 5.0394 6.5921 6.2562 5.3728 3 5.9150 5.8941 5.38936.2994 5.7845 5.9591 6.6367 4 5.6753 4.8882 4.5232 5.9794 5.9440 6.03475.1508 5 2.6698 3.9305 4.3467 4.1305 3.1839 4.5760 5.6941 6 0.83263.8304 1.7982 1.9080 1.8483 4.8500 4.2102 7 0 2.0229 0.9414 0.65050.9830 3.8334 3.6596 8 1.6485 0.2845 0 0 2.5059 1.8017

TABLE 5 % Retention - 158° F. (70° C.) aging 4 5 6 7 8 9 PLA web PLA webPLA web PLA web PLA web PLA web in S1 in S1 in S1 in S1 in S1 in S1Example Control 4 with with with with with with Aging PLA web VK-4050VK-5075 VK-7170 VK-7190 VK-7190 VK-7190 (days) in S1 (95:5) (95:5)(95:5) (99:1) (95:5) (90:10) 0 100 100 100 100 100 100 100 1 72 84 70 8168 68 84 2 77 82 83 61 80 76 65 3 72 72 65 77 70 72 81 4 69 59 55 73 7273 63 5 32 48 53 50 39 56 69 6 10 47 22 23 22 59 51 7 0 25 11 8 12 47 448 20 3 0 0 30 22

Examples 10-15

PLA spunbond nonwoven webs were prepared using the method describedabove (AP was 12 psi). The dry basis weight of the webs was about 60grams/meter². Epoxidized vegetable oils were dissolved in ethyl acetateto 0.5 wt %, 1 wt % and 2 wt % solutions, which were disposed on thewebs by soaking. The webs were then dried in an air oven at 60° C. for 5minutes. This resulted in webs having epoxidized vegetable oil contentsof 2.5 wt %, 5 wt % and 10 wt % correspondingly based on the totalweight of web plus the loaded epoxidized vegetable oil. Varying typesand amounts of epoxidized vegetable oils were used and the epoxidizedvegetable oils also had different wt % oxirane oxygen content. Wet wipeswere then prepared from the coated PLA webs using Solution 1 (S1). Wetwipes were also prepared using Solution 1 (S1) without any epoxidizedvegetable oil additive for comparison. The wet wipes were aged at 158°F. (70° C.) and tensile strength and % retention data were obtained asdescribed above. The PLA wipe compositions, tensile strength, and %retention data are provided in Tables 6 and 7.

TABLE 6 Tensile Strength (kgf) - 158° F. (70° C.) aging in Solution 1(S1) 10 11 12 13 14 15 Coated Coated Coated Coated Coated Coated PLA webPLA web PLA web PLA web PLA web PLA web Example Control 5 PLA/VK-PLA/VK- PLA/VK- PLA/VK- PLA/VK- PLA/VK- Aging Uncoated 4050 5075 71707190 7190 7190 (days) PLA web (95:5) (95:5) (95:5) (97.5:2.5) (95:5)(90:10) 0 8.2331 7.72053 6.06812 7.1274 6.7385 6.9502 7.1748 1 5.91946.50661 6.77606 6.3915 6.0356 7.9675 6.7671 2 6.3704 5.8719 5.611975.3091 5.8969 5.9760 5.5164 3 5.9150 6.51599 5.00827 5.8497 5.83686.2178 4.8855 4 5.6753 5.23444 5.77974 5.5459 5.0411 4.7404 6.3103 52.6698 5.11056 4.08648 3.6858 4.8927 4.3560 4.8191 6 0.8326 3.239233.38899 3.5453 4.6055 4.1273 4.1092 7 0 2.3650 3.4023 3.5058 4.4002 81.1583 2.5812 3.1096 3.2838

TABLE 7 % Retention - 158° F. (70° C.) aging in Solution 1 (S1) 10 11 1213 14 15 Coated Coated Coated Coated Coated Coated PLA web PLA web PLAweb PLA web PLA web PLA web Example Control 5 PLA/VK- PLA/VK- PLA/VK-PLA/VK- PLA/VK- PLA/VK- Aging Uncoated 4050 5075 7170 7190 7190 7190(days) PLA web (95:5) (95:5) (95:5) (97.5:2.5) (95:5) (90:10) 0 100 100100 100 100 100 100 1 72 84 112 90 90 115 94 2 77 76 92 74 88 86 77 3 7284 83 82 87 89 68 4 69 68 95 78 75 68 88 5 32 66 67 52 73 63 67 6 10 4256 50 68 59 57 7 0 33 50 50 61 8 16 38 45 46

Examples 16-21

PLA spunbond nonwoven webs were prepared using the method describedabove (AP was 12 psi). The dry basis weight of the webs was about 60grams/meter². Epoxidized vegetable oils were dissolved in ethyl acetateto 0.5 wt %, 1 wt % and 2 wt % solutions, which were disposed on thewebs by soaking. The webs were then dried in an air oven at 60° C. for 5minutes. This resulted in webs having epoxidized vegetable oil contentsof 2.5 wt %, 5 wt % and 10 wt % correspondingly based on the totalweight of web plus the loaded epoxidized vegetable oil. Varying typesand amounts of epoxidized vegetable oils were used and the epoxidizedoils also had different wt % oxirane oxygen content. Wet wipes were thenprepared from the coated PLA webs using Solution 2 (S2). Wet wipes werealso prepared using Solution 2 (S2) without any epoxidized vegetable oiladditive for comparison. The wet wipes were aged at 158° F. (70° C.) andtensile strength and % retention data were obtained as described above.The PLA wipe compositions, tensile strength, and % retention data areprovided in Tables 8 and 9.

TABLE 8 Tensile Strength (kgf) - 158° F. (70° C.) aging in Solution 2(S2) 16 17 18 19 20 21 Coated Coated Coated Coated Coated Coated PLA webPLA web PLA web PLA web PLA web PLA web Example Control 6 PLA/VK-PLA/VK- PLA/VK- PLA/VK- PLA/VK- PLA/VK- Aging Uncoated 4050 5075 71707190 7190 7190 (days) PLA web (95:5) (95:5) (95:5) (97.5:2.5) (95:5)(90:10) 0 8.1650 6.65362 6.23088 7.5680 8.2019 8.5145 8.8851 1 7.20354.5093 6.40667 7.3903 6.4483 6.4277 7.7954 2 6.2132 3.24408 3.613416.0700 6.1770 5.0689 5.2061 3 3.5920 2.03559 1.06699 3.5659 4.80185.3336 4.5335 4 1.7399 0.58129 0.47218 1.2129 3.2257 3.8005 5.2281 50.7926 0 0 0.3736 1.2296 3.5428 3.2105 6 0.2434 0.1895 0.5695 2.45673.6578 7 0.0000 0 1.5439 2.6655 8 0.8790 1.9650

TABLE 9 % Retention - 158° F. (70° C.) aging in Solution 2 (S2) 16 17 1819 20 21 Coated Coated Coated Coated Coated Coated PLA web PLA web PLAweb PLA web PLA web PLA web Example Control 5 PLA/VK- PLA/VK- PLA/VK-PLA/VK- PLA/VK- PLA/VK- Aging Uncoated 4050 5075 7170 7190 7190 7190(days) PLA web (95:5) (95:5) (95:5) (97.5:2.5) (95:5) (90:10) 0 100 100100 100 100 100 100 1 88 68 103 98 79 75 88 2 76 49 58 80 75 60 59 3 4431 17 47 59 63 51 4 21 9 8 16 39 45 59 5 10 0 0 5 15 42 36 6 3 3 7 29 417 0 0 18 30 8 10 22

The complete disclosures of the patents, patent documents, andpublications cited herein are incorporated by reference in theirentirety as if each were individually incorporated. Variousmodifications and alterations to this disclosure will become apparent tothose skilled in the art without departing from the scope and spirit ofthis disclosure. It should be understood that this disclosure is notintended to be unduly limited by the illustrative embodiments andexamples set forth herein and that such examples and embodiments arepresented by way of example only with the scope of the disclosureintended to be limited only by the claims set forth herein as follows.

What is claimed is:
 1. A fiber comprising: a core comprising analiphatic polyester; and an epoxidized fatty ester having greater than4.7 wt-% oxirane oxygen, based on the total weight of the epoxidizedfatty ester; wherein the epoxidized fatty ester is disposed on thesurface of the fiber core in an amount of at least 0.5 wt-%, based onthe total weight of the fiber; wherein the epoxidized fatty ester ispresent in an amount that provides a nonwoven web of a plurality of saidfibers with greater tensile strength after aging at a temperature of135° F. for at least 25 days in an aqueous cleaning and/or disinfectingsolution compared to a nonwoven web made of fibers of the same aliphaticpolyester without the epoxidized fatty ester to an extent of greaterthan 10%.
 2. The fiber of claim 1 wherein the epoxidized fatty ester hasat least 5.5 wt-% oxirane oxygen.
 3. The fiber of claim 1 wherein theepoxidized fatty ester has up to 23 wt-% oxirane oxygen.
 4. The fiber ofclaim 1 wherein the epoxidized fatty ester is an epoxidized poly(fattyester).
 5. The fiber of claim 1 wherein the epoxidized fatty ester ispresent on the fiber in an amount of up to 20 wt-%, based on the totalweight of the fiber.
 6. The fiber of claim 1 wherein the epoxidizedfatty ester is present on the fiber in an amount of at least 1 wt-%,based on the total weight of the fiber.
 7. The fiber of claim 1 whereinthe aliphatic polyester is selected from the group of poly(lactide),poly(glycolide), poly(lactide-co-glycolide),poly(L-lactide-co-trimethylene carbonate), poly(dioxanone),poly(butylene succinate), poly(butylene adipate), poly(ethyleneadipate), polyhydroxybutyrate, polyhydroxyvalerate, and blends andcopolymers thereof.
 8. The fiber of claim 7 wherein the aliphaticpolyester is a poly(lactide).
 9. The fiber of claim 1 wherein thealiphatic polyester has a number average molecular weight of at least8,000 Daltons.
 10. The fiber of claim 1 wherein the aliphatic polyesteris present in an amount of at least 80 wt-%, based on the total weightof the fiber.
 11. The fiber of claim 1 wherein the fiber core furthercomprises a shrink reduction additive.
 12. A web comprising a pluralityof the fibers of claim
 1. 13. The web of claim 12 which is a nonwovenweb.
 14. A wet wipe comprising: a nonwoven web of claim 13; and anaqueous composition comprising water and a surfactant and/or a biocide;wherein the aqueous composition contacts the nonwoven web.
 15. A wetwipe comprising: a fibrous web comprising fibers, wherein each fibercomprises a core comprising an aliphatic polyester; and an aqueouscomposition contacting the fibrous web, wherein the aqueous compositioncomprises: water; a surfactant and/or a biocide; and an epoxidized fattyester having greater than 4.7 wt-% oxirane oxygen, based on the totalweight of the epoxidized fatty ester; wherein the epoxidized fatty esteris dispersed in the aqueous composition in an amount of at least 0.5wt-%, based on the total weight of the aqueous composition; wherein theepoxidized fatty ester is present in an amount to provide a fibrous webthat demonstrates greater tensile strength after aging at a temperatureof 135° F. for at least 25 days in an aqueous cleaning and/ordisinfecting solution compared to a fibrous web made of fibers of thesame aliphatic polyester without the epoxidized fatty ester to an extentof greater than 10%.
 16. A process for improving the hydrolyticstability of a wet wipe comprising a fibrous web, wherein the fibrousweb comprises fibers comprising an aliphatic polyester, the methodcomprising: forming a fibrous web comprising fibers comprising analiphatic polyester; providing an aqueous composition comprising: water;an epoxidized fatty ester in an amount of at least 0.5 wt-%, based onthe total weight of the aqueous composition; and a surfactant and/or abiocide; wherein the epoxidized fatty ester has at least 4.7 wt-%oxirane oxygen, based on the total weight of the epoxidized fatty ester;and contacting the fibrous web with the aqueous composition to depositthe epoxidized fatty ester thereon; wherein the epoxidized fatty esteris present in an amount to provide a fibrous web that demonstratesgreater tensile strength after aging at a temperature of 135° F. for atleast 25 days in an aqueous cleaning and/or disinfecting solutioncompared to a fibrous web made of fibers of the same aliphatic polyesterwithout the epoxidized fatty ester to an extent of greater than 10%.